Tri-naphthylamine



' Patented Mar. 17, 1931 No Drawing. Original application filed March 14, 1323, Seria1 No.. 347, 1 83 filed December 23; 1929.-Seria1 N'o. 416,2315

ALBERT M. CLIFFORD, or AKRON, orirq nssrenon TO rniieeoonxnea Trans; RUB- BER COMPANY, or AKRON, cure, a eoaroan'rio v oromo TRI-NAPHTHYLeMiNE This invention relates to a new'class of chemical compounds, and llLllZLS particular relation to the provision of anew class of compounds peculiarly adapted to be used as antioxidants or age retarders in rubber compounds. o

This application is a division of application Serial No. 347,188, filed March'l l, 1929. One object of the invention is to provide an antioxidant which is simpleto manufacture, the use of which results in a product having exceptionally high resistance to the deleterious eflects of oxygen, sunlight and other Weather agencies.

Another object of the invention is to provide a class of efficient antioxidants or age retarders which are substantially -free from disagreeable odors and toxic effects upon the I workmen employed in handling them.

Heretofore,it has beenIobse-rved that cer: tain compounds such as hydroquinone and reaction products of aldehydes (such as fur-V furaldehyde) and aromatic amines (alpha naphthylamine) when incorporated into rubber, materially retard the aging effects produced by atmospheric oxygen and sunlight.

Another class of compounds which have also been found usefulfor this purpose is that of 1 the aromatic amines,.such as beta-naphthylamine. Some of these compounds are objectionable because it is difficult to reduce them v toa sufficiently fine degree of sub-division to permit of their uniform distribution 7 through the rubber compound. Also, some of them arev objectionable because of disagreeable odors which they possess and because they discolor the rubber.

' This inventionconsists in the discoveryof a new class of tertiary aromatic aminesfparticularly the tri-naphthylamines and their use as antioxidants for rubber compounds.

These substances are quite efficient in their age. retarding effects and may be incorporated into rubber compounds with the greatest of ease. In addition, they are also substantially non-odorous. Tri-naphthylamines are found in certain proportions (approximately 10%) in'the unpurified dinaphthylamines manufac-v tured from naphthol and anhydrous ammonia and this application by the: application lofj heatand pressure in an A o'pending-application Serial No. 274, 7 I

which-it crystallizes .upon standing. The

material is obtained in .theform of fine white crystals having aidefinite melting'pointlof from 238?; to235 G. Solutionsof the.com-. pound show 'a da'rk blue fluorescence-when they aregheld up to the light. The crystalline.

material itself fluore'sices' a brilliant" light blue when exposed to-ultra violet-light. It

is quite soluble1in aromatic-hydrocarbons but is. comparatively. insoluble in-ethyl alcoho]; The materialsmay bezusedas anti-.

oxidantsin fmostof-the standard rubber com-.

pounds:fl.The following is an example o f a;

which their use assures excellent! formula in l sa l'es Orr bber compdand, pass in accordance'with the preceding formula in as an antioxidant,weresubjected to vulcaniwhich tri-betamaphthylamine was employed zation for various "periods of time. These samples were then subjectedto tests to ascertain their elongation and tensile strength before they were subjected to the action of oxygen.

. A second set of samples vulcanized under exactly the same conditions were first weighed t and were then placed in an oxygen bomb and subjected to artificial aging. for a period of six days at a temperature of 50 C. and at a pressure of. lbs. per sq. in- The samples were then weighed a second time to ascertain the percentage of oxygen absorbed after which they were subjected to physical tests to ascertain 7 their elasticity and tensile strength after artificial aging. w

Cute Stress in kgsJemJ at Pfiil'ceflt Pei-peat G ODE. we1g Time ggg f 500% -7oo% Break atbreak increase in mins. S P9 elong. elong. q. in.

. '35 ,40- 12 1 48 109 880. 5o 16 56 135 s 40 26 es 170 800 AFTER AGING, V

The results of these tests are contained in the following table:

v -;F romthese tables itvvillbe apparent that a W the percent'of oxygen absorbed by samples was comparatively small even under the relatively severe conditions existing in an oxygen bomb. Also, the artificially aged samples retained to anexceptional degree their original tensile strength and elasticity. Under similarconditions, samples containing no antioXidantWere reduced to resinous masses substantially devoid of elasticity or tensile strength.

, These compounds may also be employed as antioxidants in s0aps,transforme r oils and. slmllar organic compounds which are sub ect' to deteriorationdue to oxidation. e

Although I have described in detail only the preferred embodiments of the invention,

ical compound, tri-naph itwill be apparent to those skilled in the art that it is not so limited but that various 

